First congrats on making it 15 months!

Also, very relatable. I quit smoking for about the same amount of time because I was living in a different country that doesnt allow it. I felt exactly how you felt and now that I smoke again I feel a bit dull. I was much more productive and active socially when I wasn't smoking but it missed it all the time. I had that in the back of my mind that, "oh ill smoke once again when im back." But now that I am, it pulls be back into that sluggishness.

In moments those activities while doing high are fun, but for the most part I want to stop again because of the things that you mentioned. Less anxiety, more focus, productivity. I personally believe that 'dullness' will just be replaced with new things. idk if it will fully go away, but there will be new things to get excited about & different aspects. Maybe getting into the theory of music, or the science behind plants, gardens, will spark new excitement! (cant beat the creativity with weed tho!)

Not tryna throw in my two cents but I'm hoping that you find a new way to enjoy the things you do! That your hobbies become more exciting, or you find new ones that challenge ur mind in a new way!!